Process of making levulose, glucose, &amp;c.



' To all whom it may concern:-

UNITED STATES PATENT OFFICE.

FRANCIS L. STEWART, oF nURRYsviLLE, PENNSYLVANIA, AssIcNoR or ONE-H ALF TO SAMUEL E. GILL, OF PITTSBURG, PENNSYLVANIA.

Specification of Letters Patent.

Patented Feb. 18, 1908.

' Applicationfiled November 12. 1906. Serial No. 342.963.

Be it. known that I, Framers L. SrEwAnT, of Murrysville, Westmoreland county, Pennsylvania, have invented a new and useful Proc-- ess of Making Levulose, Glucose, &c., from' the Jerusalem Artichoke, of which the 'following is a full,clear, and exact description.

My inventionrelates to utilizing the J erusalem articho e (Helicmthus tuberosus). for

the manufacture of saccharine products, which may either be concentrated into syrup or converted into alcohol.

Incarrying out my invention, 1 take the artichoketubers at maturity, that is, when. the stocks are dead, andreduce them to a pulp by any suitable step, such as raspingor grinding. The tubers may be used either in the fresh condition as taken from the ground, or they may be dried either as tubers or after being sliced or ground to pulp. The fine pulp is then mixed with water, which if the tubers are in the wet condition is preferably about equal in volume to. that of the tubers. If the tubers have been dried, the wateris preferably about double their volume. The mixture is preferably made in a heating tank or digester, and a-solution of oxalic acid is then added in a sufiicient amount to cause the solution to redden blue test paper.' After the oxalic acid is added the mixture is then heated, to a temperature'ofabout 212 degrees Fahrenheit, preferably for about three hours if the heating tank is open or about half that time if a closed tank or digester' isemployed, in which it is subjected to about 80 to 100 pounds steam pressure; A lime or aluminium salt is then added, preferablv in the form of hydrate of alumina, or hydrate of' carbonate of lime. The salt is preferably added graduall to the mixture, which stirred during 15 is time, to an amount sufiicient to make the solution neutral to test paper. The liquid is then strained off from the pulpy matter and the wet pulp then subjected to a hydrostatic pressure to recover the remainder of the liquid. By these steps,

the substance known as inulin, which forms the main constituent in the juice of the tubers, together with a small proportion of another carbohydrate known as synanthrose, are converted directly into levulose and dextrose. The levulose ranks next to cane sugar in value as a commercial product, thus rendering valuable for practical use tubers which 212 degrees F., and filtered,

at the present time are utilized only for stock feeding.

If the solution is tobe converted into a saccharine-syrup, I then preferably treat ,it in a wooden tank with tannic acid until the solution shows an acid reaction. I then add 'a sufficient amount of silicate of soda or other soluble silicate, to perfect the clarification. Lime, preferably in the form of milk of lime, or a soluble salt of alumina, such as hydrate of alumina, is then added until'the liquid is again neutral. It is then reheated to about through bone black.

-- The clarified saccharine solution thus obif tained, which consists chiefly of levulose with a small proportion of glucose, is then reuum apparatus, to a form of thick or dense syrup; v

The advantages of my invention result from the utilizing for commercial purposes of a tuber which'has heretofore been used only for stock-feeding purposes. These tubers contain a large amount of inulin, which is utilized by my method to give a valuable product. The use of oxalic acid I have found tobe of especial advantage as it preferably duced by evaporation, preferably in a .vac-

may be entirely removed, whereas other acids, such as hydrochloric acid or sulfuric acid, would give deleterious constituents in the syrup. The process-may be rapidly and cheaply carried out.-

Different types of apparatus may be employed for carrying out my invention.

' I claim 1. In the method of obtaining saccharine pro ducts from Jerusalem artichokes, the steps which comprise reducing the tubers to pulp,

adding water and oxalic acid thereto, heating the mass, adding an alkaline salt and then separating the saccharine solutionfrom the pulp and insoluble (precipitate.

2. In the metho of obtaining saccharine products from Jerusalem artichokes, the

steps which comprise reduci the tubers to a pulp, addi water and oxalic acid, heating the mass, ad 'ng an alkaline salt, separating the saccharine solution from the pulp and insoluble precipitate, reacidifying the solution,

clarifyingthe same, .and again neutralizing the clarified solution.

, r 3. In the method of obtaining saccharine products from Jerusalem artichokes, the

steps which comprise reducing the tubers to I apulp, addin water and. oxahc' acid, heating the mass, ad 'ngan alkaline salt, separati the saccharine solution from the pulp an 5 insoluble precipitate,.adding tannic acid to the solution, clarifying it with a soluble silicate, and again neutralizing the solution. 4. In the method of obtaining saccharine products from Jerusalem artichokes, the

' 10 steps which comprise reducing the tubers to a pulp, addin water and oxalic acid, heating the mass, ad ing an alkaline salt, separating the saccharine solution from the pulp and insoluble precipitate, adding tannic acid to 5, the solution, clarifying'it with a soluble silicate, again neutralizing thesolution, and

then reheating and filtering it. a

5. The method of obtaining saccharine products from Jerusalem artichokes, which consists in reducingthe tubers to-a pulp,' 0 adding water and oxalic acid, heating the mass, neutralizing with an alkaline salt,

separating'the saccharine solution from the pulp and insoluble precipitate, reacidifying the solution with tannic acid, clarifying t 5 with a soluble silicate, again neutralizing it with an alkaline salt, reheating it, filtering it through bone black, and finally concentratin the filtered saccharine solution.

in testimony whereof, I have hereunto set 30 myhand.

I L. STEWART. Witnesses: q 7

J OHN MILLER,

H. CORWIN, 

